Memory device manufacturers often desire to guarantee that a certain number of memory cells in a memory array will work when the memory array is used at almost any temperature. To achieve this, a memory device manufacturer tests a set of memory arrays to sort out those that do not have a minimum number of reliable memory cells. In operation, a number of test memory cells in a memory array are written to and read from, and those memory arrays whose test memory cells do not perform as desired are discarded. However, such sorting is difficult when the behavior of the memory cells varies across temperature and the memory cells are tested at a single temperature setting. For example, if a memory cell is more difficult to program or read at colder temperatures than at warmer temperatures, the number of memory cells that will fail increases as temperature decreases. Accordingly, the fact that a memory array passes the memory device manufacturer's test at a single temperature setting does not guarantee that the memory array will perform as desired when used in the field at lower temperatures.
There is a need, therefore, for a method and system for temperature compensation that will allow a memory device manufacturer to more reliably sort memory arrays.